Relay having a plurality of sealed contact switches

ABSTRACT

An industrial relay including a plurality of hermetically sealed contact switches therein. The relay further includes a ferromagnetic structure having a bottom member, first and second side members extending upward from the bottom member, and first and second top members extending toward each other from the side members and defining respective first and second pole faces and a gap therebetween. Each of the top members has a top surface and first and second side surfaces. The first pole face is in a plane perpendicular to the side surfaces and at an acute angle with the top surface of the first top member, while the second pole face is in a plane perpendicular to the top and side surfaces of the second top member. An energizing coil is positioned around the bottom member of the ferromagnetic structure. A plurality of the sealed contact switches are directly affixed to the top and side surfaces of the top members and adjacent the pole faces. The above-described components are containable in a suitable enclosure.

Bowers Oct. -8, 1974 [54] RELAY HAVING A PLURALITY OF SEALED CONTACTSWITCHES [75] Inventor: Gerald Joe Bowers, Bloomington,

[73] Assignee: General Electric Company, New

. York, NY.

[22] Filed: Sept. 26, 1973 [21] Appl. No.: 400,904

[52] US. Cl 335/152, 335/153, 335/281 [51] Int. Cl. H01h 51/22 [58]Field of Search 335/l51-154,

[5 6] References Cited UNITED STATES PATENTS 3,146,327 8/1964 Ohki etal. 200/241 3,264,425 8/1966 Hosokawa et al. 335/153 3,472,141 10/1969Hilbig et al. 335/281 Schlamp; R. G. Simkins [5 7] ABSTRACT Anindustrial relay including a plurality of hermetically sealed contactswitches therein. The relay further includes a ferromagnetic structurehaving a bottom member, first and second side members extending upwardfrom the bottom member, and first and second 'top members extendingtoward each other from the side members and defining respective firstand second pole faces and a gap therebetween. Each of the top membershas a top surface and first and second side surfaces. The first poleface is in a plane perpendicular to the side surfaces and at an acuteangle with the top surface of the first top member, while the secondpole face is in a plane perpendicular to the top and side surfaces ofthe second top member. An energizing coil is positioned around thebottom member of the ferromagnetic structure. A -plurality of the sealedcontact switches are directly affixed to the top and side surfaces ofthe top members and adjacent the pole faces. The above-describedcomponents are containable in a suitable enclosure.

9.1?!aims7 Dreiv nef urs RELAY HAVING A PLURALITY OF SEALED CONTACTSWITCHES BACKGROUND OF THE INVENTION 1. Field of the Invention Theinvention relates to relays, and more particularly to relays having aplurality of sealed contact switches included therein.

2. Description of the Prior Art An industrial relay which has aplurality of sealed contact reed switches positioned in the proximity ofthe pole faces of a U-shaped magnetic structure has been previouslymanufactured. GEnerally the U-shaped magnetic structure, due to therelatively large distance between the pole faces, provides a relativelyhigh reluctance path for the magnetic lines of flux passing therethroughwhen the coil of the relay is energized. The' magnetic circuit createdby this particular type of structure thereby produces a relatively lowinductive reactance in the electric circuit of the device and cannot beexpected to provide adequate filtering for current pulses originating inan AC source which is connectable to the coil winding of the relaythrough a full wave rectifier bridge.

Furthermore when as many as four sealed contact switches are used in onerelay, they are usually positioned over the pole faces of the abovedescribed ferromagnetic structure. This requires that the width of thestructure be of sufficient dimension for reliably mounting all of thesealed contact switches thereon. Under these circumstances the overallcross-sectional dimension of the structure is relatively large therebycausing the coil to have a relatively long mean turn length. Thisresults in an increase in the resistance of the coil per turn ratiosince the average turn is relatively far from the structure.

Still further when it is desired that one of the sealed.

contact switches is to be adapted to operate in a normally closed mode,a permanent bar magnet is attached to the insulative housing of thatswitch. If that switch is not sufficiently magnetically isolated fromany adjacent sealed contact switch, the bar magnet can interfere withthe proper performance of any adjacent switch.

OBJECTS OF THE INVENTION It is therefore an object of this invention toprovide an improved relay which includes a plurality of sealed contactswitches, wherein a ferromagnetic structure associated with the switchesis shaped to produce a relatively high inductive reactance circuit whichis used to filter DC current pulses introduced from a rectified AC powersource.

It is another object of this invention to provide an improved relaywhich includes a ferromagnetic structure that has a reducedcross-sectional area for a given number of sealed contact switchesmounted thereon, thereby resulting in a shorter mean turn length for acoil positioned around the ferromagnetic structure.

It is a further object of this invention to provide sufficient magneticisolation between the adjacent sealed contact switches positioned on theferromagnetic structure so that any switch which has been adapted tooperate in a normally closed mode will not interfere with the operationof any other switch adjacent thereto.

Other objects of the invention will ge pointed out in and understoodfrom the following.

SUMMARY OF THE INVENTION In accordance with a broad aspect of theinvention there is provided an improved relay comprising a plurality ofsealed contact switches affixed to a ferromagnetic structure. Thestructure includes a bottom member, first and second side membersextending upward from the bottom memher, and first and second topmembers extending toward each other from the side members and definingrespective first and second pole faces and a gap therebetween. Each ofthe top members has a top surface and first and second side surfaces.The first pole face is in a plane perpendicular to the side surfaces andat an acute angle with the top surface of the first top member. Thesecond pole face is in a plane perpendicular tothe top and side surfacesof the second top member. An energizing coil is positioned around thebottom member of the ferromagnetic structure. The sealed contactswitches are directly affixed to the top. and either one or both of theside surfaces of the top members and adjacent their pole faces. It ispreferable that the switches which are to be adapted to operate in anormally closed mode be placed along the side surfaces of the topmembers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective viewof those components which comprise the ferromagnetic structure andenergizing coil for the relay;

FIG. 2 is an assembled perspective view of the components shown in FIG.1;

FIG. 3 is a partial enlarged view of another embodiment of the gap andpole faces for the ferromagnetic structure shown in FIG. 2;

FIGS. 4, 5 and 6 are respective top, front and side views of thestructure shown in FIG. 2 after a plurality of sealed contact switcheshave been affixed thereto;

FIG. 7 is a perspective view of a housing enclosure for the relay.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 4 through 6,a relay 10 is comprised of a ferromagnetic structure 12, coils l4 and 16and a plurality of sealed contact reed switches 18, 20, 22 and 24. I

Structure 12 is made of any suitable magnetic material such as laminatedsilicon steel, and, as shown in FIG. 1, is initially comprised of afirst section 26 and a second section 28. Section 28 is U-shaped, whilesection 26 is C-shaped with its lower leg portion 30 extending outbeyond the remainder of section 26. As shown in FIG. 1, coil 14 has aslot 32 for receiving lower portion 30 of section 26 and coil 14 isassembled on lower portion 30. Similarly coil 16 has a slot 34 thereinfor receiving a lower portion 36 of section 28, and coil 16 ispositioned on lower portion 36 of section 28. After the above describedpositioning of coils l4 and 16 on the respective lower portions 30 and36 of respective sections 26 and 28, ferromagnetic structure 12 isformed by joining respective end faces 38 and 40 of respective lowerportions 30 and 36 to form a unitary piece as shown in FIG. 2. Sections26 and 28 can be joined at theirrespective end faces 38 and 40 usingsuitable mechanical fastening means or bonding agents.

One such suitable bonding agent is a methyl acrylic compound sold underthe brand name Eastman 910 adhesive and manufactured by the ChemicalsDivision of the Eastman Kodak Company. This bonding agent has theadvantage that it cures almost immediately. Another suitable bondingagent for this purpose, and which also cures almost immediately, is atwo part product made by CIBA Products Company, the first part being anAraldite epoxy resin 6004 and the second part being an Araldite hardener956, wherein the proportion of resin to hardener is to l.

The finally assembled ferromagnetic structure 12 shown in FIG. 2 iscomprised of a bottom member 42, upwardly extending side members 44 and46, and top members 48 and 50 which have their open faced ends 52 and 54extending toward each other and forming the pole faces for the structurewhen the coils are energized. Top member 48 includes a top surface 56and adjacent respective first and second side surfaces 58 and 60.Similarly top member 50 includes a top surface 62 and adjacentrespective first and second side surfaces 64 and 66. Pole face 54 is ina plane approximately perpendicular to top surface 62 and side surfaces64 and 66 of top member 50, while pole face 52 is in a planeapproximately perpendicular to side surfaces 58 and 60 and at an acuteangle with top surface 56 of member 48. Pole face 52 is at an angle ofapproximately 45 with top surface 56, in this instance, but this anglemay vary depending upon physical and magnetic requirements of structure12. Also pole faces 52 and 54 define an air gap therebetween such thatthe closest portions of the pole faces in this instance are spacedapproximately 0.2 inches apart.

At this point it should be noted that while pole face 54in FIG. 2 isshown to be perpendicular to the top and side surfaces of top member 50,alternatively, as shown in FIG. 3, top member 50 can instead have a poleface 68 which is similarly perpendicular to side surfaces 64 and 66 andat an acute angle with respect to the plane of top surface 62.

While two separate coils l4 and 16 are shown in this embodiment, theycan be replaced by a single coil if so desired. As a matter of fact, inthis instance, electrical terminals 70 and 72 of coil 14 areelectrically interconnected in series with electrical terminals 74 and76 of coil 16 when there is need for only a single energizing coil.However in those instances when the relay is required to have a latchingfunction coils l4 and 16 are not electrically interconnected, and coil14 is used as the latching coil while coil 16 is used as the unlatchingcoil. The coils typically are energized hy a DC power source or from theoutput of a full wave rectifier bridge which has its input connected toan AC power source and a voltage transient suppresion device. Onesuitable voltage transient suppression device is a metal oxide varistorsuch as a GE MOV Type VP varistor sold by the General Electric Company.

After coils l4 and 16 and structure 12 are assembled together, elongatedinsulative housings 78, 80, 82 and 84 of respective sealed contactswitches 18, 20, 22 and 24 are positioned directly against andpermanently attached to top members 48 and 50 adjacent their respectivepole faces 52 and 54 using a suitable mechanical fastening means orbonding agent. The housings in this specific illustrative embodiment areformed of glass and the above referred to bonding agents are alsosuitable for affixing these glass housings to the top and side surfacesof top members 48 and 50. More specifically, switch 18 is affixed toside surfaces 58 and 64 of respective top members 48 and 50, switches 20and 22 being affixed to top surfaces 56 and 62 of respective top members48 and 50, and switch 24 is affixed to side surfaces 60 and 66 ofrespective top members 48 and 50. All of the sealed contact switches areof the same construction as that of switch 18 which is shown in FIG. 4,and they are also of the same type and operate in the same manner as theswitch described in copending U.S. patent application Ser. No. 345,997of Robert C. Guichard, filed Mar. 29, l973 and assigned to the Assigneeof the present invention. To the extent necessary to understand thepresent invention, the switches will be briefly described as followswith specific reference to switch 18. Each switch includes first andsecond respective magnetic reed members 86 and 88. One end 90 of member86 is positioned externally of housing 78, and the other end 92 ofmember 86 is positioned within housing 78. One end 94 of member 88 ispositioned extrnally of housing 78, and the other end 96 of member 88 ispositioned within housing 78. Innermost ends 92 and 96 of respectivereed members 86 and 88 are overlapping, and when relay coil 14 isdeenergized, ends 92 and 96 are spaced apart to define a gap whereby thereed switch is adapted to operate in a normally open contact mode. Foroptimum performance, overlapping ends 92 and 96 of respective reedmembers 86 and 88 are located approximately equidistant betweenrespective pole faces 52 and 54 of structure 12. Furthermore reedmembers 86 and 88 are positioned approximately parallel to the plane ofthe top surfaces of top members 48 and 50. Each of the switches furtherincludes a contact button 98 attached to reed member 86 adjacent end 92.One end of a spring member 100 is fastened to reed member 88, while theother end of spring member 100 extends beyond end 96 of reed member 88and has a contact button 102 attached thereto and in juxtaposition withcontact button 98. Again for optimum performance, member 86 ispositioned closer to the pole faces of structure 12 than is spring 100.While spring 100 is preferably formed of silver, any non-magnetic springmaterial having similar properties and characteristics can be used.

While switches 18, 20 and 22 are of the normally open mode when coil 14is deenergized, switch 24 has been converted to the normally closed modewhen the coil is deenergized in the following manner. A permanent barmagnet 104 is bonded to housing 84 of switch 24. The bonding agent usedto attach magnet 104 to housing 84 can be identical to the bondingagents used to affix the sealed contact switches to structure 12. Barmagnet 104 is so positioned on housing 84 that its north magnetic poleis oriented opposite the south magnetic pole of the electromagnet formedby energized coil 14 and structure 12, while the south magnetic pole ofbar magnet 104 is oriented opposite the north magnetic pole of theelectromagnet. Thus, in operation when the coil is deenergized, themagnetic flux, which flows from the north magnetic pole to the southmagnetic pole of bar magnet 104, passes through the magnetic reedmembers and provides sufficient force to cause the overlapping ends ofthe magnetic reed members to be in contact whereby the switch is in thenormally closed mode of operation. Upon energization of the relay andthe flow of current through coil 14, magnetic flux,

which then flows through the magnetic circuit comprising structure 12and the magnetic reed members of the sealed contact switches, interactswith the opposing magnetic flux from bar magnet 104. The resultant fluxfield flowing through the magnetic reed members of 5 sealed contactswitch 24 is then insufficient to keep the overlapping ends of the reedmembers in contact and the sealed switch is biased to the open mode ofoperation. Upon deenergization of the relay, the magnetic flux flowingthrough structure 12 collapses, whereby the resultant magnetic fluxflowing between the poles of bar magnet 104 and through the magneticreed members of switch 24 is again sufficient to cause the closing ofthe sealed contact switch.

At this point it should be noted that switches 18, and 22 can similarlybe converted to operate in the normally closed mode by affixing similarbar magnets to their respective housings. For optimum performance,sealed contact switches 18 and 24, which are affixed to the sides of thetop members of structure 12, are better strategically located foroperation in the normally closed mode than are sealed contact switches20 and 22. This is so because there is greater magnetic isolationbetween a bar magnet affixed to the housing of either of sealed contactswitches 18 or 24 and their adja- 25 cent sealed switches than is thecase if a bar magnet were affixed to the housing of either of sealedcontact switches 20 and 22.

After the relay is completely assembled, it is containable in a suitableenclosure of any convenient standard type such as that illustrated inFIG. 7, wherein the terminals of the coils and the external ends of thesealed contact switches are conventionally electrically connected toexternal terminals 106 of the relay enclosure. The enclosure canactually consist of a plurality of suitable molded plastic parts 108which are held together by standard fasteners 110.

By extending top members 48 and 50 towards each other until they definethe relatively small gap therebetween, it is easier for the magneticflux flowing through structure 12 when coil 14 is energized to flow ontothe top surfaces 56 and 62 of top members 48 and 50 and then through thereed members of sealed contact switches 20 and 22. This results in anincrease in inductive reactance and in the efficiency of the relaysmagnetic circuit. The higher inductive reactance provides for improvedfiltering of current pulses that are electrically coupled to the windingof the energizing coil from a rectified AC power source.

Furthermore, by providing that the plane of at least one pole face is atan acute angle with the top surface of its respective top member, someof the magnetic lines of flux flowing through structure 12, when thecoil is energized, are forced to the side surfaces of the structure,thereby rendering it possible to successfully operate sealed contactswitches 18 and 24 on the respective side surfaces of top members 48 and50. Therefore, by being able to operate switches 18 and 24 on the sidesurfaces of the top members of structure 12, there is an increase inmagnetic isolation between adjacent switches when either or both ofswitches 18 and 24 are adapted to operate in the normally closed mode.Also it is possible for the width and, in fact, the cross section ofstructure 12 to be greatly reduced from the dimension previouslyrequired to accomodate the same number of sealed contact switches sideby side in a single plane. This reduction in the cross section ofstructure 12 also desirably results in a reduction of the mean turnlength of the coils, a lower resistance per turn ratio, more turns percoil, longer length of coil, and ultimately improved dissipation ofheat,iall of which result in an improved relay.

Although the invention has been described with reference to specificembodiments thereof, numerous modifications are possible withoutdeparting from the invention and it is desirable to cover allmodifications falling within the spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A relay comprising:

a. a ferromagnetic structure including a bottom member, first and secondside members extending upward from said bottom member, and first andsecond top members extending toward each other from said side membersand defining respective first and second pole faces and a gaptherebetween, each of said top members having a top surface and firstand second side surfaces, at least said first pole face being at anacute angle with the top surface of said first top member;

b. an energizing coil positioned around a portion of said structure; and

c. a plurality of sealed contact switches directly affixed to the topand at least said first side surfaces of said top members and adjacentsaid pole faces.

2. A relay according to claim 1, wherein said first pole face is in aplane approximately perpendicular to the side surfaces of said first topmember.

3. A relay according to claim 2, wherein said second pole face is in aplane approximately perpendicular to the top and side surfaces of saidsecond top member.

b. a first magnetic reed member having one end ex- I tending within saidhousing;

c. a first contact fixed adjacent said one end of said first magneticreed member;

d. a second magnetic reed member having one end extending within saidhousing and overlapping said one end of said first magnetic reed member;

e. a non-magnetic spring having one end attached to said second magneticreed member within said housing and another end extending beyond theoverlapping ends of the first and second magnetic reed members; and i f.a second contact attached to said other end of said spring, said secondcontact being in juxtaposition with said first contact.

6. A relay according to claim 5, wherein said magnetic reed members arepositioned approximately parallel to the top and side surfaces of saidfirst and second top members.

7. A relay according to claim 5, wherein the overlapping ends of saidmagnetic reed members are positioned approximately equidistant betweensaid respective first and second pole faces.

8. A relay according to claim 5, wherein said first in a normally closedmode when said coil is deenermagnetic reed member is positioned closerto said top gized members than is q Spring 10. A relay according toclaim 9, wherein said one of 9. A relay according to claim 5, furthercomprising a bar magnet attached to a portion of the Surface of saidswitches is attached to either of the first and sec- Said housing f atleast one f Said Sealed Contact 0nd side surfaces of said first andsecond top members. switches, whereby said one switch is adapted tooperate

1. A relay comprising: a. a ferromagnetic structure including a bottommember, first and second side members extending upward from said bottommember, and first and second top members extending toward each otherfrom said side members and defining respective first and second polefaces and a gap therebetween, each of said top members having a topsurface and first and second side surfaces, at least said first poleface being at an acute angle with the top surface of said first topmember; b. an energizing coil positioned around a portion of saidstructure; and c. a plurality of sealed contact switches directlyaffixed to the top and at least said first side surfaces of said topmembers and adjacent said pole faces.
 2. A relay according to claim 1,wherein said first pole face is in a plane approximately perpendicularto the side surfaces of said first top member.
 3. A relay according toclaim 2, wherein said second pole face is in a planE approximatelyperpendicular to the top and side surfaces of said second top member. 4.A relay according to claim 2, wherein said second pole face is in aplane approximately perpendicular to the side surfaces and at an acuteangle with the top surface of said second top member.
 5. A relayaccording to claim 1, wherein each of said sealed contact switches isfurther comprised of: a. an electrically insulating housing; b. a firstmagnetic reed member having one end extending within said housing; c. afirst contact fixed adjacent said one end of said first magnetic reedmember; d. a second magnetic reed member having one end extending withinsaid housing and overlapping said one end of said first magnetic reedmember; e. a non-magnetic spring having one end attached to said secondmagnetic reed member within said housing and another end extendingbeyond the overlapping ends of the first and second magnetic reedmembers; and f. a second contact attached to said other end of saidspring, said second contact being in juxtaposition with said firstcontact.
 6. A relay according to claim 5, wherein said magnetic reedmembers are positioned approximately parallel to the top and sidesurfaces of said first and second top members.
 7. A relay according toclaim 5, wherein the overlapping ends of said magnetic reed members arepositioned approximately equidistant between said respective first andsecond pole faces.
 8. A relay according to claim 5, wherein said firstmagnetic reed member is positioned closer to said top members than issaid spring.
 9. A relay according to claim 5, further comprising a barmagnet attached to a portion of the surface of said housing of at leastone of said sealed contact switches, whereby said one switch is adaptedto operate in a normally closed mode when said coil is deenergized. 10.A relay according to claim 9, wherein said one of said switches isattached to either of the first and second side surfaces of said firstand second top members.